A computer user working with an application program that produces one or more screens of information may enter a selection of an immediate screen. The processed video data signal delivered by the computer to the primary monitor that relates to the selected screen is concurrently written into a memory. The application program may next-advance to display another screen, or another application program. Meanwhile the previously selected screen of processed video signal data is stored in a digital memory and continues to be read-out from the memory and reconstituted as a replication of the processed video data signal selected by the user. This replicated signal is subsequently presented to a secondary monitor for viewing as a predecessory document.
The user may then move ahead to view or edit subsequent portions of the same document or a different document on the primary video monitor. In addition, different software originated windows of information are maximizable and separately displayable on each the primary and secondary video monitors. The device performance stands absolutely independent from operating system constraints. It has been found to be equally valuable for use with programs running under Windows(copyright), MS-DOS, Unix, Linux, CP/M86, OS/2, Apple-OS, Macintosh(copyright) and other operating systems where a processed video signal either in graphical or ASCII format is coupled between the computer and a monitor. A current screen data signal is also obtainable through the computer""s parallel LPT ports or serial COM ports. A SHIFT+PRINT_SCREEN keyboard command is ordinarily submitted through keyboard entry to initiate an export of pertinent video data by way of the computer""s printer port. This video data is stored in memory and readout on the secondary video monitor. A primary display video screen selection is made by actuation of an auxiliary key-switch associated with the adapter, by a xe2x80x9cthirdxe2x80x9d mouse button entry or by a unique keyboard sequence entry processed by a TSR program to enable the necessary function. Expansion to several secondary video monitors is obtainable through usage of additional memory and control circuitry whereby several preceding document pages or windows of information are simultaneously displayed, enabling more efficient editing or comparison between disparate document portions.
Computers are much used in offices and other business settings, as well as for personal use, in preparing documents, writing letters, completing forms and searching data. Computers also find substantial application in desktop publishing of newsletters, brochures and advertising literature. In each of these cited usages, it is often desirable if not absolutely necessary to reference against another document page, or even another class of document. In the earlier text-based computers running MS-DOS, UNIX, etc. it was common practice to xe2x80x9cprint outxe2x80x9d a hard copy of the reference page. This approach was superceded by Windows(copyright) software that allowed the layering of two or more related pages. None of these earlier approaches gave a truly concurrent view of a xe2x80x9cbeforexe2x80x9d and xe2x80x9ccurrentxe2x80x9d document. Real time concurrency between two disparate screens has not been practicable, at least not until now.
Windowing OS Application
Common practice in contemporaneous computers is to utilize windowing-capable Operating System xe2x80x9cOSxe2x80x9d software. Windowing type Graphical User Interfaces xe2x80x9cGUIxe2x80x9d, initially developed by Xerox Corporation and first appearing commercially on early Apple Macintosh(copyright) computers provides a user with a near-concurrent view of two or more screens of data/derived from one or more separately running programs. Subsequently the windowing GUI was further developed and more importantly, popularized as a defacto standard of the personal computer industry by Microsoft Corporation. Recognize that Microsoft Windows(copyright) appears in one version or another in a vast majority of the worlds desktop, personal and portable computers. A current trend is a rapid increase in the installation of a Linux OS, an open architecture freeware version of Unix, in commercial network and workgroup systems. This suggests that Linux (and Unix) may command a substantial portion of the client workstation applications in the near future. Linux provides a GUI having most of the GUI features of other competitive windowing format OS software. A most popular Linux GUI is xe2x80x9cX Window Systemsxe2x80x9d, a freeware program available from Red Hat Software Inc. and others. In addition Corel Corporation supplies xe2x80x9cWordPerfect-8xe2x80x9d for Linux, which extends the potential for Linux applicability to many more critical usages, such as intranet applications within law firms and the like. A primary advantage afforded by Linux in such critical applications, for example, is the xe2x80x9ccrash resistancexe2x80x9d Linux (or Unix) affords over a typical Microsoft Windows Operating System, while maintaining a goodly degree of compatibility between Microsoft Windows based files and Linux. In contrast, negligible compatibility exists between an Apple OS based applications file and either Microsoft Windows or Linux. Further Linux information may be determined at the Linux website: www. linux.org and the Corel Corporation""s website: www.linux.corel.com. 
Word processors, spread sheet programs, data base programs and other applications oriented software programs frequently include various windows of related data information which is brought up to full screen size for viewing. These windows are used like a reference, usually viewed in a passive state. That is to say, they are not necessarily subject to immediate editing efforts.
In concurrent application operation, where two or more file editor programs (e.g., word processor, data base, spreadsheet, etc.) are running at the same time, disparate displays are produced which may indirectly relate to one-another via dissemination to the computer""s user through a video display and subsequent keyboard entry into an instant program data stream by the user. Letters or other documents stored in more than one word processor or database file are frequently needed to tie together a user""s thought process.
Multiple Window Displays
Popular windowing graphical user interface GUI xe2x80x9coperating systemxe2x80x9d software, such as Microsoft Windows(copyright) 3.11, Windows98(copyright), Windows2000(copyright), Unix and Linux (and lesser used Apple-Macintosh, iMac(copyright) and IBM-OS/2 software), is known to do a heretofore acceptable job of enabling cross-document examination by enabling a user to open one or more additional document windows. This prior art approach is fraught with a major shortfall manifesting itself as an practicable difficulty in providing a user with a quick ease of readability. This objectionable usability factor arises due to a fragmented screen appearance introduced by subwindow layers and an implicit and distracting need for switching back and forth between one or more subwindows typically introduced by the necessitous window partitions situate on the main display screen. As a practical result, the user is frequently xe2x80x9cjumping back and forthxe2x80x9d between the top window and one or more individual under-layers of sub-windows, with an attendant distraction from the central work effort of editing or assembling a principal document""s text and associated train of thought.
Microsoft Word(copyright) or Corel WordPerfect(copyright) running rounder an appropriate version of Microsoft""s Windows(copyright), (viz, Windows-3.1,-3.11,-95,-98,-2000,-NT, etc.) as well as Corel WordPerfect(copyright) running under a version of Linux (such as Red Hat Linux 5.2) typify this class of wordprocessor editors. An inevitable result of awkward multi-window editing which routinely occurs while using these (and similar) types of programs frequently drives the user to make a print-out of a temporary hard-copy support document. This obvious expedient, while wasteful of time and paper, is also less efficient to use than what an eye-level xe2x80x9con screenxe2x80x9d presentation of an immediate predecessory document could provide. The intermediate hardcopy is sometimes produced through expedient use of the SHIFT+PRINT_SCREEN keyboard command now provided on most IBM-type personal computer systems, or through the use of a program""s xe2x80x9cprintxe2x80x9d command typically by limiting the printout to the page of immediate interest.
It is in this sort of xe2x80x9ccomparativexe2x80x9d application, where it may be desirable if not necessitous to view a supplementary document while typing-in or editing a primary document, that a xe2x80x9cmultiple viewing screenxe2x80x9d provision may introduce a new level of convenience and operating efficiency into a user""s everyday workload. In a practical sense, this translates into a better budget of time, speedier editing actions and general cost savings for any business where the user is an employee.
Windows98 Multiple Monitor Display
Microsoft Windows98(copyright) provides the software support necessary to use up to nine monitors. The monitors may be set up like a big desktop, or a different program might run on each monitor. This may enable the use of a wordprocessor on one monitor, a spreadsheet on another and a data base program on yet another monitor. A principal drawback to this approach for multiple monitor operation is that the user must have installed a separate PCI graphics adapter for each monitor. Furthermore, the multiple monitor feature of Windows98(copyright) only supports PCI graphics adapters in which the input data signals are raw (unprocessed) video data signals derived from the computer""s PCI bus.
The obvious shortfall of this Windows98(copyright) based multiple monitor system is inherent in the incapacity for the approach to be used universally with multiple monitors deriving their video signals from other operating systems such as Linux, MS-DOS, Mac-OS, etc. Additionally, this approach works seamlessly only with applications programs that have provisions for the multiple monitor mode, which negates its applicability to a widespread base of pre-existing programs. Nor will this approach work with proprietary operating systems frequently used with commercial applications, such as found in banks and similar non-Microsoft dependent computer systems.
The user will immediately recognize a superiority of this invention""s teachings over that of the prior art advanced by Windows98(copyright) is the ability to work with virtually any computer and monitor combination, irrespective of the operating system and application program combinations.
Non-Window Operating Systems Displays
Many xe2x80x9cprofessionalxe2x80x9d software programs used for data management and similar serious business purposes are written in a native language code, i.e. in something like Cobol, Pascal, Fortran, xe2x80x9cCxe2x80x9d, xe2x80x9cC++xe2x80x9d or any of several other programming languages. Typically, these sort of programs run directly under non-windowing bare-bones operating systems such as Microsoft""s MS-DOS(copyright), Digital Research""s CP/M86, UNIX and LINUX. As is well known, use of these more basic operating systems when run with a well written Assembly language source code or a compiled language such as xe2x80x9cCxe2x80x9d can lead to far faster and functionally more efficient operational performance with significantly less susceptibility to xe2x80x9ccrashesxe2x80x9d and other annoying malfunctions typical of Windows(copyright) dependant programs.
The sheer size of the Windows(copyright) operating system files (e.g., several hundred megabytes) and considerable graphical interface oriented data processing makes a more basic operating system preferable when functional speed and operational reliability are of paramount essence. In comparison with the enormous file size requirements, a decent non-windows operating system such as MS-DOS can ordinarily be contained in files of merely a few megabytes in size.
Some custom programs are written with pseudo-windows action (e.g., windows-like functionality not derived from an underlying Windows(copyright) or Macintosh operating system). This has been a long known software artform, used in the earliest IBM-PC type computers having basic monochrome graphics capability, such as provided by the then-popular Hercules graphics video adapter.
Notwithstanding these custom programs, it is well known that most non-Windows(copyright) oriented programs have little or no windows-like capability, or ability to display more than an immediate screen of information on a monitor. Concurrent operation of disparate programs to provide near simultaneous monitor display is even more exceptional and ordinarily not applicable to conventional non-windows applications programs.
Providing Concurrent Multiscreen Display
My invention now overcomes this deficiency, allowing the concurrent display of an immediate screen of information on the primary monitor and a predecessory screen of information on a secondary monitor, all without benefit of a dependence upon a Windows(copyright) or Macintosh(copyright) operating system""s support. In its most basic operating form, assume you want to view the content of a data file while you type a letter on a word processor. Using this invention, you first open the data file and present it on the primary monitor. When you are satisfied with the screen appearance (e.g., the information you seek is visible), you grab the video signal and store it for readout and replicate display on the secondary monitor. In effect the display becomes xe2x80x9clocked ontoxe2x80x9d the secondary monitor. Next, the word processor is loaded and you view your work document or letter on the primary monitor while you may review data held on the secondary monitor""s screen.
Unambiguous Predecessory Display
In reiteration, I realized that a far superior method for providing a computer user with serviceable interactive cross-file editing is attained if the predecessory reference or support document data display is supplied near eye-level as an unambiguous presentation on the secondary video monitor. Meanwhile the primary monitor is used solely for display of the main, or working, document data.
Sneaker Networking
In a primitive form, this dual document display arrangement is sometimes clumsily implemented through a xe2x80x9csneaker networkxe2x80x9d approach, wherein the immediate data file is manually transferred from xe2x80x9ccomputer Axe2x80x9d and carried over to xe2x80x9ccomputer Bxe2x80x9d by using a floppy-disk, ZIP-Disk(copyright), or the like which is used to temporarily hold data and allow an operator to manually transfer the data into a separate computer system where it might be separately displayed adjacent with the primary display as predecessory data. This is a long-used approach and its limitations and convenience shortfalls are well known, not the least of which is the requirement for a wholly separate and necessarily similar second computer system which is loaded with and running (a separate copy of) a similar application software program in order to effect a generally useful presentation of the reference document data file. In this prior art arrangement, the main computer is used for a principle editing or data entry function, while the second computer serves merely to display contents of the reference document.
Local Area Workgroup Networking
In another setup, the data being displayed on the main computer might be networked or ported to the second computer for supplementary display. In a configuration emulating my invention, this setup is treated like a xe2x80x9cone-person workgroupxe2x80x9d. In other words, the same operator is using two or more computers in the same network, viewing the xe2x80x9cpreviousxe2x80x9d and xe2x80x9cpresentxe2x80x9d data on separate monitor screens. Networking data does require special and costly network adapter hardware and suitable network software support, which necessitates more advanced user skills. For example, each computer in such a peer network (even if used on the same desk by the same person) must be equipped with an EtherNet LAN 10Base-2, 10Base-T or IEEE 802.3 compliant adapter card, i.e., a Boca Research Inc. xe2x80x9cBOCALANcardxe2x80x9d or equivalent, and suitable operating software, such as Microsoft Windows for Workgroups, Windows-NT, Windows-98, UNIX, Linux, Novell NetWare and other NDIS and ODI compliant systems. If the network ported data is stored in the slave computer, then predecessory readout may be simulated whereby the display on the master computer may advance ahead of the slave computer. Herewithin, predecessory refers to a historical store or supplementary display of video data which are succeeded or replaced by a subsequent updated or alternate main display. While either of these arrangements can be effective, they each involve substantial hardware duplicity and inherent expense in form of a functionally similar but fully separate computer system hardware, software and related maintenance. Furthermore, a time-consuming necessity for loading or networking a database or program copy containing the reference document data into the second computer system demands time consuming operator training and additional user effort and experience level.
Simple User Interface
These prior approaches obviously do not imitate the essential eloquence of my translative video adaptor (hereinafter TVA or xe2x80x9cthe adaptorxe2x80x9d) invention. In these inferior heretofore configurations a considerable interactive manipulation of both computers is necessary to merely emulate the antecedent or predecessory display of an previously viewed screen of data on the slave computer""s monitor.
As a result of these shortcomings of the prior art, my TVA stands alone as unique and not merely an obvious extension of the cumbersome and inefficient prior art that heretofore merely utilizes one variation or another of local area networking.
To be truly useful and efficient, the user ought to be able to display a predecessory, reference document with a minimum of time consuming effort, prior skill and requiring a minimal amount of xe2x80x9clearning curvexe2x80x9d effort in order to get meaningful results. The predecessory display ought to be presentable on a second monitor in a manner which is functionally transparent and operationally unpresumptuous to the average user. In other words, aside from a simple keystroke command or xe2x80x9cclickxe2x80x9d entry via a control device such as a mouse button, the user effort needed for updating of screen data on the second monitor ought to occur without distracting the user from a thought train that may better be focused on the principal document task.
TVA Supports a Slave Monitor
I find that a more efficient and economical form of cross-document data file referencing is readily to obtainable by using a secondary display monitor which is uniquely coupled as a slave to a stored video signal provided by my TVA invention and sampled directly from the computer system""s primary display monitor""s fully processed video data stream, as opposed to obtaining the raw video data signal from the computer""s internal data bus signals. In other words, the processed video data is preferably fully conditioned and formatted as xe2x80x9cmonitor video signal input readyxe2x80x9d.
External TVA Interface
A paramount advantage of my invention over known prior art is the intrinsic capability for it to be engineered in variant forms which works equally well with virtually any operating system and in any computer hardware configuration albeit standard or oddball in arrangement. My invention supports all common video formats through appropriate design of the hardware details, including color VGA, EGA, SVGA, CGA, etc. It works well with either monochrome graphics such as Hercules graphics or strictly ASCII-text based displays. Additionally, it is reasonable to design my invention so that a shared unit may be usable with several different video formats.
A preferred embodiment for my invention is as a stand-alone accessory device that simply plugs in series with the video cabling. In other words, a short video xe2x80x9cjumperxe2x80x9d cable may connect between the computer""s video output connector (usually a DB9 or DB15 form) and an input to my TVA device. The primary monitor and the secondary monitor then each plug into appropriate mating connectors outputted from my TVA device. A foremost advantage of this preferred embodiment of a standalone TVA device is that it can be provided as an independently functional standalone accessory having a form factor about the size of a large cigarette pack that can be hooked-up using a minimum of skill, usually foregoing the usual need for obtaining costly shop service to xe2x80x9cinstall somethingxe2x80x9d, such as an adapter card into one of a PC""s available xe2x80x9cslotsxe2x80x9d.
TVA Stores Full Video Screen Frame
My TVA typically includes sufficient video memory space to ordinarily store at least one full screen of monitor-ready processed video data which are used to produce a separate and usually antecedent video data stream for writing a predecessory image screen on the second display monitor. I also find that grabbing a screen (or frame) of video information is conveniently accomplished through an expedient of providing the user with a separate control button (maybe a third xe2x80x9cmousexe2x80x9d button) which is manually actuated to initiate the immediate grabbing of the video frame representing the screenful of video data of interest.
Software Operated Predecessory Image Transfer
I also find that the initiation of a frame-grab event may be convenient when it is software implementable, particularly when the TVA is an external device. The frame grab may initiate through a response by a TSR routine singularly responsive to a unique keystroke combination that initiates a xe2x80x9cgrab signalxe2x80x9d output through the computer""s serial port. In practice the TVA is serially coupled with the primary monitor""s processed video line and provides a replicate processed video signal to a secondary monitor. Additionally, the TVA is coupled with the RS232C serial output port (usually COM1 or COM2 or equivalent) or a Universal Serial Bus USB port. The grab signal is thus delivered through the serial port and initiates the screen data storage command for the TVA memory to provide predecessory video data for the secondary monitor.
Internal TVA Functions Like xe2x80x9cExternalxe2x80x9d TVA
The TVA may be configured so as to allow it to be internally installed as a plug-in circuit card in one of the computer""s expansion bus slots. An internally installed TVA is distinctly different in conceptual approach from merely being equivalent to and performing like a second video card, as suggested in the past by Microsoft and others. This distinction is implicit in that the TVA essentially taps-into and accepts a sample of display-ready processed video which ordinarily routes from the computer""s usual video processor circuitry directly to the primary video monitor for immediate presentation. In other words, in the usual computer configuration the video tap is made external to the computer hardware, usually via a cable jumper between the TVA and the usual video processor card""s output connector.
In this arrangement of my invention, the primary monitor and the secondary monitor each plug-into separate connectors usually sited on the TVA card""s mounting plate. In this arrangement, a control signal might be obtained directly from the internal card bus as submitted by the TSR software routine. Alternatively, an external xe2x80x9cgrab switchxe2x80x9d may be connected with the TVA card to permit absolute user controlled manual screen data grab initiation.
A most fundamental intent for my TVA is to avoid a variety of predecessory display errors which a plurality of separate xe2x80x9cvideo adapterxe2x80x9d cards operating from raw bus signals may introduce.
Real-Time Processed Video is Utilized
It is urgent to realize and bears repeating that my invention, whether internally mounted as a plugin card or externally located, strictly samples the real-time, processed and monitor-ready video data signal ordinarily delivered from the output of the video adapter card. My TVA stores a true xe2x80x9cwhat you seexe2x80x9d frame sample for subsequent xe2x80x9cwhat you getxe2x80x9d display on a secondary monitor as an accurate replica of a predecessory image that has been recently displayed on the primary monitor. In other words, the INPUT to my TVA device is derived directly from the OUTPUT of the computer""s usual video adapter card as monitor-ready processed video signals.
The physical interface is most often embodied as a short jumper cord extending between the video output and my TVA input. As a result of this operational distinction unique to my invention my TVA must not be misinterpreted as merely xe2x80x9cjust another form of video cardxe2x80x9d.
With the internally located TVA a transient-stay-resident (henceforward TSR) subroutine program may conveniently serve to implement video frame grabbing in unique response to certain predeterminable patterns of keystroke sequence entries, such as ALT+SHIFT+PRINT_SCREEN, for example. Although a TSR triggered instruction obtained from the computer""s control bus is utilized to trigger my invention into action it remains to be absolutely understood that it is the post-processed video signal which is grabbed, sampled and temporarily stored. By definition my invention obtains this post-processed video signal ordinarily from the output of the computer""s usual xe2x80x9cvideo cardxe2x80x9d. In contemporaneous computers, this video signal is ordinarily in VGA, SVGA or EGA format or an equivalent technical variation or operational extension and including monochrome graphics or ASCII character based displays.
Separate Computers Compound Video Errors
Additional discrepancies wrought by the prior art methodologies using separate computers may occur as a result of even minor system set-up differences, or due to fundamental variations in image processing technique, particularly between video cards of different brands and models, or of even the same brand picked from different production lots where the video processing algorithm may be-slightly changed.
Emulate Hardcopy Printout as Display
Instead of obtaining the video data signal from the video signal port as the predecessory screen signal, the TVA may alternatively couple with the computer""s PARALLEL printer port LPT1 or SERIAL RS-232C port COM1, or a Universal Serial Bus USB connection. In this usage, a SHIFT+PRINT_SCREEN keyboard instruction urges a current screen data stream to be processed so as to flow forth to the parallel (or serial) port. As with tapping into the video adapter""s output, this provides an equivalent screen of data which is subsequently stored in an ancillary video memory portion of the TVA. In a xe2x80x9cgraphics modexe2x80x9d a printer signal delivered in this hookup is quite similar to the primary monitor""s video signal and for practical purposes may be considered equivalent. In a standard ASCII screen presentation (e.g. a typical 80 column,l 24 or 25 row alphanumerical screen of data) the characters flow forth from the printer port and may be subsequently stored in my TVA""s memory.
The printer port data stored in the TVA memory is subsequently read out and reconstituted in a video format suitable for scanning the monitor screen display. The major difference in this approach is that a xe2x80x9cWYSWYGxe2x80x9d graphics or ASCII alphanumerical printer signal output is relatively slow compared with the video signal format. In effect, this means the screenful of printer data is read-into the TVA memory rather slowly, while its monitor-ready video signal is read-out very much faster. This is merely an engineering consideration that leaves the essence of my invention""s objects unscathed.
Albeit a substantial compromise in video format, this variant approach for practicing the essence of my invention is comparable in usefulness to initiating a SHIFT+PRINT_SCREEN directive to send data to a hard-copy printer. In my invention""s practice the information xe2x80x9cprintsxe2x80x9d instead to my invention""s TVA and is retained in the TVA memory and subsequently read-out onto the screen of the second display monitor.
Utilizing the printer-equivalent output for my TVA""s video source does provide the computer user with a preview of what a hard-copy printout might look like. As a result, editing of layout and other factors may be exercised prior to xe2x80x9cwastingxe2x80x9d an actual hard copy printout.
Remarkable Use with Individual Workstation
Workstations, or individual computer systems, which are networked in an intranet with a central server that ordinarily holds many files in a common data storage facility may substantially benefit from my invention""s application. It is frequently beneficial for a network user to have an ability to uniquely display and hold an individual frame of data on a separate slave type video monitor for more convenient reference, comparison or editing purposes. In other words, a user of a workstation tied into a network can divert the workstation video to my invention""s TVA and subsequently view a predecessory workstation screen on a secondary monitor.
A keynote advantage of this usage of my invention with a typical workstation is that aside from providing the user with a reference display of a document on the secondary monitor, it accomplishes this goal without tying up network resources. This network oriented, shared database use of my TVA and a separate monitor screen is a fundamental characteristic of my invention that is just as important for the workstation user as it is with an individual user of a stand-alone personal computer.
My invention pertains to computer systems which display information on video monitors and most particularly to personal computers, personal office computers and individual workstations, including those which are networked with a server or mainframe. I tend to focus this invention""s teaching towards IBM-compatible computers and workstations typically using Intel, AMD or Cyrix architecture microprocessors merely because this is unequivocally the most popular and widely used PC hardware at the time of my invention. My invention is equally applicable to other less popular systems, including the Apple Macintosh(copyright) and iMac(copyright) which, while being little more than a niche computer having a relatively tiny installed market share, can clearly benefit from multiple-display service for better user convenience.
Various Operating Systems
More importantly my invention applies to a plethora of operating systems including various versions of Microsoft Windows(copyright), Apple-OS and IBM OS/2. It also applies to non-windows system programs such as UNIX, LINUX, CP/M86, MS-DOS, Sun-OS and a variety of other proprietary operating systems.
The underlying intent of my TVA invention is to intentionally redisplay a predecessory screen of video derived from a processed video line ordinarily coupled between a computer and a monitor. The TVA device works equally well with and affords about the same operational benefit to both windows and non-windows applications programs.
Secondary Monitor for Predecessory Display
A secondary video display monitor of ordinary design is typically used in conjunction with my Translative Video Adaptor (TVA) to grab and indefinitely store individual selected frames of data ordinarily delivered to the usual computer""s main monitor. In other words, it is the TVA device alone which supports the essence of my invention and the applicable to secondary monitor may be universally picked from an array of screen sizes and features as provided by any number of makers. The stored data are subsequently read-out and displayed on the secondary (i.e., supplementary or satellite) monitor to serve to display full screens of pre-occurring reference information which enables a user to conveniently evaluate or edit other usually immediate program data which are subsequently displayed on the computer""s main (i.e., primary or first) display monitor.
Translative Video Adapter
I have coined the term Translative Video Adapter (TVA) to succinctly phrase it""s technical performance. In effect, my TVA accepts the processed video signal from the computer, firstly translates the video signal into a binary format for digital memory storage. The digital memory is subsequently read-out and the retrieved binary format data is then secondly translated back into a reconstructed processed video signal format that serves to drive the secondary, or antecedent display monitor and closely replicate the predecessory screen of data.
A TVA Card is Not a Video Card
As an adjunct to a computer utilizing a VGA (video graphics array) or equivalent display, my TVA may be conveniently built upon a plug-in printed circuit assembly which is temporarily inserted into one of the available expansion bus slots ordinarily associated with a typical personal computer (including Compaq, Packard-Bell, Acer, Dell, AST-Research, Gateway, and Hewlett-Packard PC clones based upon or compatible with an original IBM-PC, IBM-AT or IBM-PS/2 design). In an unequivocal distinction between my TVA and prior xe2x80x9cvideo adapter cardsxe2x80x9d, I preferably interface the processed video signal directly.
A jumper cable may couple directly between my TVA card video input and the computer""s usual VGA type of video display card""s analog video output terminal. The jumper cable serves to convey analog RGB (red-green-blue) processed video signal levels from the video display card""s usual output directly to my TVA card""s input. In this arrangement a principal advantage resides in the ability to obtain necessitous operating power levels directly from the internal expansion bus connector.
The original or principal VGA video monitor is subsequently plugged into a connector provided on my TVA card. A separate sample of each of the analog R,G and B video signals is grabbed by an input of each of three high speed video ADC (A/D converters). The digital output from the ADC is then coupled with a video memory bank which is appropriately sized to hold the necessary video data bytes for supporting at least one full video frame. The memory is repeatedly read out to three video speed DAC (D/A converters) which return the video signal back to its analog RGB signal format for application to the secondary VGA video display monitor.
TSR Routine Enables Predecessory Frame Grab
Video frame grabbing can be initiated by the user through a unique keystroke sequence (say, ALT+SHIFT+PRINT_SCREEN) producing an unique PC keyboard scan code sequence (i.e., 38+2A+E0xe2x80x942A E0xe2x80x9437 and hereinafter called Alt_Shft_PScr) manually entered via keyboard and coupled through the computer""s main data bus. A TSR (transient stay resident) software subprogram compatible with the installed operating system is ordinarily utilized to act on the selected keystroke recognition. The TSR instructions may be transparently setup in the computer""s high memory through installation of a suitable code line in the computer""s usual AUTOEXEC.BAT or equivalent batch file.
My TVA device, when embodied as the mentioned to plug-in card, may be particularly convenient when the computer is intended to service CGA (color graphics adapter), EGA (extended graphics adapter), MGA, (monochrome graphics adapter, such as Hercules), or even ASCII-based MDA (monochrome display adapter) dependent display monitors. These earlier types of monitors continue to find substantial, albeit dwindling commercial usage, particularly for database, data entry, programming code preparation and basic word processing applications.
Faithful Rendition of Predecessory Screen Display
The eloquence of my invention is that a faithful duplication of whatever video processing the computer""s usual built-in video circuitry provides is absolutely duplicated so as to precisely replicate the primary display presentation on the secondary display monitor. Ordinarily, a frame of video is grabbed and stored in my adaptor""s video memory in response to instructions received from a software TSR routine in recognized response to a unique keystroke sequence such as the mentioned Alt_Shft_PScr (example) routine. Otherwise, in absence of software provision, the TVA may be triggered to grab a frame of video signal ordinarily routed to the principal monitor in response to actuation of a portable keybutton-switch, additional mouse-button, or the like usually located near or includable as part of the user""s keyboard. The memory stored signal is then continually read-out and buffered to suitable video signal levels and fed to the secondary display monitor where it is accurately rendered for content, color and shading. This provides a true image for the operational convenience of the user.
External TVA Device is Flexible
An external TVA may be provided which intermediately couples between the computer""s usual VGA video adapter""s DB-15 video OUTPUT receptacle and the VGA or SVGA video display monitor signal line plug. In this preferable arrangement, the video signal coupled with the TVA is ordinarily in analog format and suitable A/D (analog to digital) conversion is performed. A video memory stores data sufficient for at least one complete video frame. At a minimum a 640xc3x97480 pixel frame may require about 692 kilobytes of memory to support 256 colors, while a 1024xc3x97768 pixel frame may require at least 5.3 megabytes or so of storage for the same extent of color resolution. The stored memory output data are subsequently utilized with a D/A (digital to analog) converter to reconstruct the analog video signal for immediate coupling with a separate secondary video display monitor. In this arrangement, a separate manual xe2x80x9cupdatexe2x80x9d key-switch convenient to the operator may be actuated to grab a new frame for storage and display on the secondary monitor. Conversely, a connection between the TVA and a serial COM port might be utilized together with a TSR software routine to obtain operation from a unique keyboard entry combination, such as the mentioned Alt_Shft_PScr routine which encourages a frame grab trigger signal to deliver from the COM port.
A similar external adaptor may also be readily designed to couple with the TTL signal level video monitor output lines provided on many earlier personal computers. Since the usual video signals are inherently binary in these earlier display monitors, they do not require A/D conversion but rather can obviously be engineered to couple directly with the memory. The output of the memory is then read-out and further conditioned back to a TTL level appropriate for application to the secondary TTL level video display monitor. A separate key-switch located near the operator, or an additional mouse-button may be actuated to grab a new video frame or screen for storage and display on the secondary, monitor. Alternatively, a control signal connection between the TVA and an output port such as the usual serial COM port or USB port might be established together with a software TSR routine to establish operation from a unique keyboard entry sequence, such as the said Alt_Shft_PScr routine.
Character Based Monochrome Display
Some widely used computer applications utilize straight ASCII-character based monochrome displays. Each character is usually 1 byte, and a typical 80 column, 25 line display produces a maximum of 2,000 characters per screen, necessitating temporal TVA storage that may be readily satisfied by a modest 16,384 kilobit (2,048xc3x978 bits) RAM device.
Alternating Monitors
Although I have thus far I have described my invention in terms of a primary display and a secondary display (or several secondary displays), I also anticipate my invention to include alternation of monitors. What this means is that two or more monitors may be used wherein the screen image on the most recently activated monitor becomes the predecessory monitor upon command initiated by the user. As a result the lowest order predecessory monitor becomes the primary monitor.
These charts depict the multi-monitor action. Under User Action, Edit infers the user is presently working on the document. Next infers the User having entered a xe2x80x9cscreen grabxe2x80x9d instruction. Under Monitor No. 1 (2 or 3) Primary means the display is active, e.g. the one being edited. View 1 means the predecessory screen data just preceding the current Primary view. View 2 means the predecessory screen data just preceding the current View 1. Obviously this scheme for multiple displays is extensible to any reasonable number of monitors.
Hardcopy Printout Replication
An external adaptor may be provided which obtains xe2x80x9chardcopyxe2x80x9d or equivalent data from the computer""s parallel LPT port or serial COM or USB port. In this arrangement, the video display signal which may be provided to the secondary display monitor is specifically limited to that level of information which is ordinarily sent to a printer when a usual SHIFT+PRINT_SCREEN keyboard entry is made. The binary signal provided through the parallel or serial port is conditioned and sent to the DATA input lines of a memory having sufficient capacity to store data for at least one screen of information. Initial occurrence of the screen print signal on the printer output COM or LPT line may be singularly sufficient to trigger storage of the subsequent data. Alternatively, a programmer may create a TSR software routine which can be installed in the computer to enable redirection of immediate principal video display monitor data to the appropriate COM or LPT port through keyboard entry of a unique keystroke combination, such as the Alt_Shft_PScr routine.
An objective of my invention is to sample and store a selected screen of processed video ordinarily coupled with a primary monitor and thereafter continue to display the selected screen sample on a secondary monitor.
Another objective for my invention is to utilize a processed video data flow between a computer and a primary display monitor as a source of data which may be sampled, stored and subsequently retrieved for later display on a secondary monitor.
An outstanding aspect of my invention is to enable multiple monitor display utilization with substantially any operating system, including all versions of Windows(copyright), MS-DOS, Unix, Linux, CP/M86, and Mac-OS(copyright) running on any personal computer or workstation platform utilizing an accessible processed video signal line (such as VGA) coupled between a video signal processor and a display monitor.
Yet another goal for my invention is to provide a user with a current and previous display of a working document on separate primary and secondary monitors utilizing a stored replication of the processed video signal as ordinarily coupled with the primary monitor to develop the secondary monitor""s display.
An extended object for my invention is to allow xe2x80x9cdisplay rotationxe2x80x9d where the primary display and secondary display alternate back and forth between a first monitor and a second monitor as the user advances through successive screens of the work document.
Another convenience provided by my invention is to enable the storage of several predecessory screens of information any one or more of which may be re-presented on the secondary monitor in response to a user""s command.
A fundamental intent for my invention is to adapt an individual frame or screen of processed video data signal flow between a computer and a primary display monitor into a storable data format and subsequently read back the stored data in a replicate processed video signal form suitable for followup display on a secondary display monitor.
Still another objective for my invention is to teach other artisans the essence of a translative video adaptor TVA which may be implemented in an unobtrusive form to intercept or grab frames of processed video signal flow between a computer and a primary display monitor whereupon the grabbed video signal frame data is temporarily stored and subsequently read-out to provide a true display of the grabbed video signal information on a secondary monitor subsequent to change of the primary display monitor data presentation.
A key object for my invention is to provide at least dual monitor display of a computer""s processed video, whereby the first monitor""s display is current and the second monitor""s display is replicate of a screen display precedingly presented on the first monitor.
An economic object of my invention is to enhance computer usability and convenience with several monitors wherein one displays an immediate video screen and another displays at least one predecessory screen of data while the overall system requires a very low threshold of computer operator skill in order to obtain a most economic level of benefit from the enhancement.
A most versatile object for my invention is to provide multi-monitor display of current and predecessory screen data with any class of operating system running any version of applications software, whether Windows(copyright) capable or not, as installed in nearly any computer platform extending from the original 8086/8088 microprocessor through the best Pentium-III or later-art microprocessor based motherboard hardware and including xe2x80x9cmainframexe2x80x9d systems and other small computers such as the 68000 or 603e microprocessor based Apple and Macintosh(copyright) systems.
A functional object for my invention is to be couplable into the processed video signal line (cable connection) usually extensible between a computer""s video processor output and the computer""s video display monitor input and furthermore providing for the necessary installation with a minimum of technical skill on the part of the installer.